Many portable electronic devices, such as cellular phones, commonly have a detachable smartcard module, commonly called a Universal Identity Module (UIM) or a Subscriber Identity Module (SIM). The module stores identification information unique to a user of the portable electronic device and may be transferred from one device to another, such as from one cellular phone to another. The portable electronic devices utilize a number of power conservation techniques to improve battery life. The module, of course, also consumes power. To reduce the current drain of the hardware module to the minimum level, the supply of power to the module must be removed. But if the module contains any internal state information, the state will be lost when the module is powered-off. It may not be easy or possible for the device to re-initialize the module since the module state may not be known to the device. In fact, it may be required that the portable electronic device not know the internal state of the module. For example, the SIM toolkit internal to a UIM maintains state information and, for security reasons, the SIM toolkit state must not be known to the rest of a cellular phone. While it is desirable to power-off the UIM for periods of time when it is not needed, thereby allowing the rest of the phone to run, the UIM cannot be powered-off since the SIM toolkit state internal to the card would be lost.
Thus, what is needed is a method and apparatus for permitting power conservation by shutting off power to a hardware module without losing the state information of the module. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.